Here's Charli XCX's first musical memory: Britney Spears, in pigtails, in her 1998 music video, …Baby One More Time.

It "blew her mind", and spurred her to borrow money from her parents at the tender age of 14 to record songs she had written. After posting the songs on MySpace, she was invited to perform a series of gigs at rave parties in London. Her parents, a concert promoter and a nurse, drove her to the venues.

Now 22, Charli XCX (born Charlotte Emma Aitchison) has penned some of the hottest pop songs of the past year. This includes Iggy Azalea's Fancy, Icona Pop's I Love It and Boom Clap, from the soundtrack to The Fault in our Stars. All of them are catchy electro pop anthems with a carefree and positive vibe, as are most of the songs in Sucker, her second album.

Her upbeat songs reflect her attitude, and the British singer notes that she always performs best when she's happy. "If I perform when I'm angry I get really sloppy on stage, and it really shows," says the rising star. "But most of the time I just feel really free when I perform."

No matter how much her music video for Breaking Rules reminds us of …Baby One More Time, Charli XCX is a far cry from Spears' girl-next-door image. There's a definite edge to her; a sense that this girl knows what she wants. It starts with the huge mass of curly black hair that she has, which used to get her into rows with her label. "Because it's a mess. I like, never even owned a hair brush," she laughs. "It's funny, having arguments with 30 year-old-men about the style of my hair. But I held my ground, and yeah, I still don't brush my hair."

Video of Charli XCX - Break The Rules [Official Video]

It doesn't stop at her hair. Charli XCX is adamant about helming her own career. "When it comes to something as personal as music, it's always better when you're in control," she says. Her stubbornness has worked because she's proven herself to be a hit maker. Her trick to being original? Not listening to a lot of music. "I listen to like four records a year on the beat, and that's kind of it," she says. "Literally I will play them over and over again until I'm tired of them. It's weird." Currently, she's listening to a lot of music from Prince, Swedish rapper Yung Lean and Rihanna.

The first ideas that come into her head are usually quite similar to the finished song. She's a believer in spontaneity and dismisses the idea of thinking out and refining a piece of music. Case in point: she wrote the whole of I Love It in under half an hour. "The quicker the better," she says.

She's already started work on her third album. "I watched Birdman on the plane over to America recently. That movie was so amazing it really blew my mind," she says. "It made me think a lot about loneliness, actually." Too bad Spears already used "My loneliness is killing me", but Charli XCX is bound to come up with something just as punchy.